Sift the self-raising flour into a bowl and make a well in the centre, place the egg and water into the bowl and beat until well combined and smooth. Set aside for 15 minutes.
Apples
Place the rice flour in bowl. Dry the apple slices and coat them with the rice flour, followed by the batter. Cook a few pieces of apple at a time in the oil for 2 minutes then drain on kitchen paper. Repeat this with the remaining pieces.
Toffee
Place the water and sugar together in a large saucepan and stir them together. Place the sugar over a high heat and allow to simmer without stirring until the sugar has dissolved and is a light golden brown. Remove from the heat and stir in the sesame seeds. Toss the apple in the toffee to coat, scoop them out one with a large perforated spoon and drop them in the iced water to set. Place on a serving plate and serve at once.